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1.
The aim of the present research work was to develop release modulated beads of losartan potassium complexed with anion exchange
resin, Duolite AP143 (cholestyramine). Chitosan was selected as a hydrophilic polymer for the formation of beads which could
sustain the release of the drug up to 12 h, along with drug resin complex (DRC). Chitosan beads were prepared using an in-liquid
curing method by ionotropic cross-linking or interpolymer linkage with sodium tripolyphosphate (TPP). The formulation of the
beads was optimized for entrapment efficiency and drug release using 32 full factorial design. The independent variables selected were DRC/chitosan and percent of TPP. The optimization model was
validated for its performance characteristics. Studies revealed that as the concentration of chitosan and TPP was increased,
entrapment efficiency and the drug release were found to increase and decrease, respectively. The swelling capacity of chitosan–TPP
beads decreased with increasing concentration of TPP. The effect of chitosan concentration and percentage of TPP solution
used for cross-linking on entrapment efficiency and drug release rate was extensively investigated. Optimized beads were subjected
to in vivo studies in Wistar albino rats to determine the mean arterial blood pressure and compared with marketed formulation. The pharmacodynamic
study demonstrates steady blood pressure control for optimized formulation as compared to fluctuated blood pressure for the
marketed formulation. 相似文献
2.
Bajerová M Krejčová K Rabišková M Muselík J Dvořáčková K Gajdziok J Masteiková R 《AAPS PharmSciTech》2011,12(4):1348-1357
The aim of this study was to develop novel hydrogel-based beads and characterize their potential to deliver and release a
drug exhibiting pH-dependent solubility into distal parts of gastrointestinal (GI) tract. Oxycellulose beads containing diclofenac
sodium as a model drug were prepared by the ionotropic external gelation technique using calcium chloride solution as the
cross-linking medium. Resulting beads were characterized in terms of particle shape and size, encapsulation efficacy, swelling
ability and in vitro drug release. Also, potential drug–polymer interactions were evaluated using Fourier transform infrared spectroscopy. The
particle size was found to be 0.92–0.96 mm for inactive (oxycellulose only) and 1.47–1.60 mm for active (oxycellulose–diclofenac
sodium) beads, respectively. In all cases, the sphericity factor was between 0.70 and 0.81 with higher values observed for
samples containing higher polymer and drug concentrations. The swelling of inactive beads was found to be strongly influenced
by the pH and composition (i.e. Na+ concentration) of the selected media (simulated gastric fluid vs. phosphate buffer pH 6.8). The encapsulation efficiency of the prepared particles ranged from 58% to 65%. Results of dissolution
tests showed that the drug loading inside of the particles influenced the rate of its release. In general, prepared particles
were able to release the drug within 12–16 h after a lag time of 4 h. Fickian diffusion was found as the predominant drug release mechanism. Thus, this novel particulate system showed
a good potential to deliver drugs specifically to the distal parts of the human GI tract. 相似文献
3.
The purpose of this work was to develop and optimize gliclazide-loaded alginate–methyl cellulose mucoadhesive microcapsules
by ionotropic gelation using central composite design. The effect of formulation parameters like polymer blend ratio and cross-linker
(CaCl2) concentration on properties of gliclazide-loaded alginate–methyl cellulose microcapsules like drug encapsulation efficiency
and drug release were optimized. The optimized microcapsules were subjected to swelling, mucoadhesive, and in vivo studies. The observed responses coincided well with the predicted values from the optimization technique. The optimized microcapsules
showed high drug encapsulation efficiency (83.57 ± 2.59% to 85.52 ± 3.07%) with low T
50% (time for 50% drug release, 5.68 ± 0.09 to 5.83 ± 0.11 h). The in vitro drug release pattern from optimized microcapsules was found to be controlled-release pattern (zero order) with case II transport
release mechanism. Particle sizes of these optimized microcapsules were 0.767 ± 0.085 to 0.937 ± 0.086 mm. These microcapsules
also exhibited good mucoadhesive properties. The in vivo studies on alloxan-induced diabetic rats indicated the significant hypoglycemic effect that was observed 12 h after oral
administration of optimized mucoadhesive microcapsules. The developed and optimized alginate–methyl cellulose microcapsules
are suitable for prolonged systemic absorption of gliclazide to maintain lower blood glucose level and improved patient compliance. 相似文献
4.
The objective of the present study was to develop once-daily sustained-release matrix tablets of nicorandil, a novel potassium
channel opener used in cardiovascular diseases. The tablets were prepared by the wet granulation method. Ethanolic solutions
of ethylcellulose (EC), Eudragit RL-100, Eudragit RS-100, and polyvinylpyrrolidone were used as granulating agents along with
hydrophilic matrix materials like hydroxypropyl methylcellulose (HPMC), sodium carboxymethylcellulose, and sodium alginate.
The granules were evaluated for angle of repose, bulk density, compressibility index, total porosity, and drug content. The
tablets were subjected to thickness, diameter, weight variation test, drug content, hardness, friability, and in vitro release
studies. The granules showed satisfactory flow properties, compressibility, and drug content. All the tablet formulations
showed acceptable pharmacotechnical properties and complied with in-house specifications for tested parameters. According
to the theoretical release profile calculation, a oncedaily sustained-release formulation should release 5.92 mg of nicorandil
in 1 hour, like conventional tablets, and 3.21 mg per hour up to 24 hours. The results of dissolution studies indicated that
formulation F-I (drug-to-HPMC, 1∶4; ethanol as granulating agent) could extend the drug release up to 24 hours. In the further
formulation development process, F-IX (drug-to-HPMC, 1∶4; EC 4% wt/vol as granulating agent), the most successful formulation
of the study, exhibited satisfactory drug release in the initial hours, and the total release pattern was very close to the
theoretical release profile. All the formulations (except F-IX) exhibited diffusion-dominated drug release. The mechanism
of drug release from F-IX was diffusion coupled with erosion. 相似文献
5.
Bovine serum albumin-loaded beads were prepared by ionotropic gelation of alginate with calcium chloride and chitosan. The
effect of sodium alginate concentration and chitosan concentration on the particle size and loading efficacy was studied.
The diameter of the beads formed is dependent on the size of the needle used. The optimum condition for preparation alginate–chitosan
beads was alginate concentration of 3% and chitosan concentration of 0.25% at pH 5. The resulting bead formulation had a loading
efficacy of 98.5% and average size of 1,501 μm, and scanning electron microscopy images showed spherical and smooth particles.
Chitosan concentration significantly influenced particle size and encapsulation efficiency of chitosan–alginate beads (p < 0.05). Decreasing the alginate concentration resulted in an increased release of albumin in acidic media. The rapid dissolution
of chitosan–alginate matrices in the higher pH resulted in burst release of protein drug. 相似文献
6.
The purpose of the present investigation was to encapsulate pure prednisolone (PRD) and PRD–hydroxypropyl-β-cyclodextrin (HPβCD)
complex in cellulose-based matrix microspheres. The system simultaneously exploits complexation technique to enhance the solubility
of low-solubility drug (pure PRD) and subsequent modulation of drug release from microspheres (MIC) at a predetermined time.
The microspheres of various compositions were prepared by an oil-in-oil emulsion–solvent evaporation method. The effect of
complexation and presence of cellulose polymers on entrapment efficiency, particle size, and drug release had been investigated.
The solid-state characterization was performed by Fourier transform infrared spectroscopy, thermogravimetry, differential
scanning calorimetry, and powder X-ray diffractometry. The morphology of MIC was examined by scanning electron microscopy.
The in vitro drug release profiles from these microspheres showed the desired biphasic release behavior. After enhancing the solubility
of prednisolone by inclusion into HPβCD, the drug release was easily modified in the microsphere formulation. It was also
demonstrated that the CDs in these microspheres were able to modulate several properties such as morphology, drug loading,
and release properties. The release kinetics of prednisolone from microspheres followed quasi-Fickian and first-order release
mechanisms. In addition to this, the f
2-metric technique was used to check the equivalency of dissolution profiles of the optimized formulation before and after
stability studies, and it was found to be similar. A good outcome, matrix microspheres (coded as MIC5) containing PRD–HPβCD
complex, showed sustained release of drug (95.81%) over a period of 24 h. 相似文献
7.
Mutalik S Manoj K Reddy MS Kushtagi P Usha AN Anju P Ranjith AK Udupa N 《AAPS PharmSciTech》2008,9(2):651-659
The purpose of this study was to develop a once daily sustained release tablet of aceclofenac using chitosan and an enteric
coating polymer (hydroxypropyl methylcellulose phthalate or cellulose acetate phthalate). Overall sustained release for 24 h
was achieved by preparing a double-layer tablet in which the immediate release layer was formulated for a prompt release of
the drug and the sustained release layer was designed to achieve a prolonged release of drug. The preformulation studies like
IR spectroscopic and differential scanning calorimetry showed the absence of drug–excipient interactions. The tablets were
found within the permissible limits for various physicochemical parameters. Scanning electron microscopy was used to visualize
the surface morphology of the tablets and to confirm drug release mechanisms. Good equivalence in the drug release profile
was observed when drug release pattern of the tablet containing chitosan and hydroxypropyl methylcellulose phthalate (M-7)
was compared with that of marketed tablet. The optimized tablets were stable at accelerated storage conditions for 6 months
with respect to drug content and physical appearance. The results of pharmacokinetic studies in human volunteers showed that
the optimized tablet (M-7) exhibited no difference in the in vivo drug release in comparison with marketed tablet. No significant difference between the values of pharmacokinetic parameters
of M-7 and marketed tablets was observed (p > 0.05; 95% confidence intervals). However the clinical studies in large scale and, long term and extensive stability studies
at different conditions are required to confirm these results. 相似文献
8.
An objective of the present investigation was to prepare and evaluate Eudragit-coated pectin microspheres for colon targeting
of 5-fluorouracil (FU). Pectin microspheres were prepared by emulsion dehydration method using different ratios of FU and
pectin (1:3 to 1:6), stirring speeds (500–2000 rpm) and emulsifier concentrations (0.75%–1.5% wt/vol). The yield of preparation
and the encapsulation efficiencies were high for all pectin microspheres. Microspheres prepared by using drug:polymer ratio
1:4, stirring speed 1000 rpm, and 1.25% wt/vol concentration of emulsifying agent were selected as an optimized formulation.
Eudragit-coating of pectin microspheres was performed by oil-in-oil solvent evaporation method using coat: core ratio (5:1).
Pectin microspheres and Eudragit-coated pectin microspheres were evaluated for surface morphology, particle size and size
distribution, swellability, percentage drug entrapment, and in vitro drug release in simulated gastrointestinal fluids (SGF).
The in vitro drug release study of optimized formulation was also performed in simulated colonic fluid in the presence of
2% rat cecal content. Organ distribution study in albino rats was performed to establish the targeting potential of optimized
formulation in the colon. The release profile of FU from Eudragit-coated pectin microspheres was pH dependent. In acidic medium,
the release rate was much slower; however, the drug was released quickly at pH 7.4. It is concluded from the present investigation
that Eudragit-coated pectin microspheres are promising controlled release carriers for colon-targeted delivery of FU.
Published: February 16, 2007 相似文献
9.
Several matrix tablet formulations (hydrophilic-based, wax-based, and three-layer tablets) were designed for controlling the
release of the highly water soluble drug, venlafaxine hydrochloride (VenHCl) for once-daily administration. The three-layer
tablets consist of non-swellable, compritol-based middle layers containing the drug to which hydrophilic top and bottom barrier
layers were applied. A 23 full-factorial design was employed for optimization and to explore the effect of different variables on the release rate
of the drug from the three-layer tablets. The optimized levels of each independent variable were based on the criterion of
desirability. The calculated values of f
1
and f
2
were 4.131 and 79.356, respectively; indicating that the release profile of the optimized PEO layered tablet formulation
is comparable to that of the target release model. The pharmacokinetic parameters of VenHCl from the optimized three-layer
tablet was compared to the marketed extended release capsule as a reference in healthy human subjects using a randomized crossover
design. In this study, the 90% confidence interval for AUC0–24 and AUC0−∞ are within (0.8–1.25), which satisfied the bioequivalence criteria. It could be concluded that a promising once-daily extended-release
three-layer tablet of the highly water soluble drug, VenHCl, was successfully designed. 相似文献
10.
Sriamornsak P Asavapichayont P Nunthanid J Luangtana-Anan M Limmatvapirat S Piriyaprasarth S 《AAPS PharmSciTech》2008,9(2):571-576
The purpose of this study was to prepare wax-incorporated pectin-based emulsion gel beads using a modified emulsion-gelation
method. The waxes in pectin–olive oil mixtures containing a model drug, metronidazole, were hot-melted, homogenized and then
extruded into calcium chloride solution. The beads formed were separated, washed with distilled water and dried for 12 h.
The influence of various types and amounts of wax on floating and drug release behavior of emulsion gel beads of calcium pectinate
was investigated. The drug-loaded gel beads were found to float on simulated gastric fluid if the sufficient amount of oil
was used. Incorporation of wax into the emulsion gel beads affected the drug release. Water-soluble wax (i.e. polyethylene
glycol) increased the drug release while other water-insoluble waxes (i.e. glyceryl monostearate, stearyl alcohol, carnauba
wax, spermaceti wax and white wax) significantly retarded the drug release. Different waxes had a slight effect on the drug
release. However, the increased amount of incorporated wax in the formulations significantly sustained the drug release while
the beads remained floating. The results suggest that wax-incorporated emulsion gel beads could be used as a carrier for intragastric
floating drug delivery. 相似文献
11.
The aim of this work was to increase the solubility, stability and permeation of resveratrol by complexation with cyclodextrin-based
nanosponges (NS). Nanosponges are recently developed hyper-cross-linked cyclodextrin polymers nanostructured to form three-dimensional
networks; they are obtained by reacting cyclodextrin with a cross-linker such as carbonyldiimidazole. They have been used
to increase the solubility and stability of poorly soluble actives. This study aimed at formulating complexes of resveratrol
with β-cyclodextrin nanosponges in different weight ratios. DSC, FTIR and X-ray powder diffraction (XRPD) studies confirmed
the interaction of resveratrol with NS. XRPD showed that the crystallinity of resveratrol decrease after encapsulation. The
particle sizes of resveratrol-loaded NS are in between 400 to 500 nm with low polydispersity indices. Zeta potential is sufficiently
high to obtain a stable colloidal nanosuspension. TEM measurement also revealed a particle size around 400 nm for NS complexes.
The in vitro release and stability of resveratrol complex were increased compared with plain drug. Cytotoxic studies on HCPC-I cell showed
that resveratrol formulations were more cytotoxic than plain resveratrol. The permeation study indicates that the resveratrol
NS formulation showed good permeation in pigskin. The accumulation study in rabbit mucosa showed better accumulation of resveratrol
NS formulation than plain drug. These results signify that resveratrol NS formulation can be used for buccal delivery and
topical application. 相似文献
12.
Gliclazide is a second generation of hypoglycemic sulfonylurea and acts selectively on pancreatic β cell to control diabetes
mellitus. The objective of this study was to produce a controlled release system of gliclazide using chitosan beads. Chitosan
beads were produced by dispersion technique using tripolyphosphate (TPP) as gelating agent. The effects of process variables
including chitosan molecular weight, concentration of chitosan and TPP, pH of TPP, and cross-linking time after addition of
chitosan were evaluated by Taguchi design on the rate of drug release, mean release time (MRT), release efficiency (RE8%), and particle size of the beads. The blood glucose lowering effect of the beads was studied in normal and streptozotocin-diabetic
rats. The optimized formulation CL2T5P2t10 with about 31% drug loading, 2.4 h MRT, and 69.16% RE8% decreased blood glucose level in normal rats for 24 h compared to pure powder of gliclazide that lasted for just 10 h. 相似文献
13.
The present investigation concerns with the development of controlled release tablets of lamivudine using acetylated moth bean starch. The acetylated starch was synthesized with acetic anhydride in pyridine medium. The acetylated moth bean starch was tested for acute toxicity and drug-excipient compatibility study. The formulations were evaluated for physical characteristics like hardness, friability, % drug content and weight variations. The in vitro release study showed that the optimized formulation exhibited highest correlation (R) value in case of Higuchi kinetic model and the release mechanism study proved that the formulation showed a combination of diffusion and erosion process. There was a significant difference in the pharmacokinetic parameters (T(max), C(max), AUC, V(d), T(1/2) and MDT) of the optimized formulation as compared to the marketed conventional tablet Lamivir(?), which proved controlled release potential of acetylated moth bean starch. 相似文献
14.
The objective of this study was to develop solid lipid nanoparticles (SLNs) of simvastatin and to optimize it for independent
variables (amount of glycerol monostearate, concentration of poloxamer, and volume of isopropyl alcohol) in order to achieve
desired particle size with maximum percent entrapment efficiency (% EE) and percent cumulative drug release (% CDR). To achieve
our goal, eight formulations (F
1–F
8) of SLNs were prepared by solvent injection technique and optimized by 23 full-factorial design. The design was validated by extra design checkpoint formulation (F
9), and the possible interactions between independent variables were studied. The responses of the design were analyzed using
Design Expert 7.1.6. (Stat-Ease, Inc, USA), and the analytical tools of software were used to draw Pareto charts and response
surface plots. On the basis of software analysis, formulation F
10 with a desirability factor of 0.611 was selected as optimized formulation and was evaluated for the independent parameters.
Optimized formulation showed particle size of 258.5 nm, % EE of 75.81%, with of 82.67% CDR after 55 h. The release kinetics
of the optimized formulation best fitted the Higuchi model, and the recrystallization index of optimized formulation was found
to be 65.51%. 相似文献
15.
The aim of this study was to investigate the applicability of acrylamide grafted moth bean starch as controlled release matrix former. Lamivudine was used as model drug and its controlled release tablets were formulated using various concentration of grafted copolymer. The grafted copolymer was tested for acute toxicity and drug-excipient compatibility study. The formulations were evaluated for physical characteristics like hardness, friability, % drug content and weight variations. The in vitro release study showed that the optimized formulation exhibited highest correlation (R) value in case of Higuchi model and the release mechanism study proved that the formulation showed a combination of diffusion and erosion based release process. There was a significant difference in the pharmacokinetic parameters (Tmax, Cmax, AUC, Vd, T1/2 and MDT) of the optimized formulation as compared to the marketed conventional tablet Lamivir®, which confirmed controlled release potential of acrylamide grafted copolymer. 相似文献
16.
Himanshu Gupta M. Aqil R. K. Khar Asgar Ali Aseem Bhatnagar Gaurav Mittal Sanyog Jain 《AAPS PharmSciTech》2009,10(2):540-546
In situ gel-forming systems have drawn much attention of current researchers to overcome the poor bioavailability from the conventional
eye drops. The present work described formulation and pharmacoscintigraphic evaluation of timolol-maleate-loaded chitosan/hydroxy
propyl methyl cellulose (HPMC)-based polymer matrix for enhanced ocular retention. Chitosan and HPMC ratio was optimized and
formulation was characterized for various in vitro parameters. The ocular retention was studied on New Zealand rabbits by gamma scintigraphy, which is a very simple and noninvasive
technique. For scintigraphy study, the drug timolol maleate was radiolabeled 99mTc by direct labeling method using SnCl2·2H2O as reducing agent. The labeling procedure was optimized to get maximum labeling efficiency (>98%). In vitro stability of the radiolabeled drug (99mTc-timolol maleate complex) was checked and it was found to be stable for up to 24 h. Plain drug eliminates rapidly as significant
activity was recorded in kidney and bladder after 2 h of ocular administration. It was evident from the scintigraphic images
and the time–activity curve plotted from the data that the plain drug solution cleared very rapidly from the corneal region
and reached into systemic circulation via nasolachrymal drainage system, as significant activity was recorded in kidney and
bladder after 2 h of ocular administration. Developed formulation cleared at a slow rate and remained at corneal surface for
longer time duration. No radioactivity was observed in systemic circulation after 2 h. Ocular irritation of the developed
formulation was also checked by hen’s egg chorioallantoic membrane test and formulation was found to be practically nonirritant.
The study signified the potential of gamma scintigraphy in evaluation of novel drug delivery systems in a noninvasive manner. 相似文献
17.
The purpose of this research was to explore theapplication of ionic interactions between naproxen sodium (NS) and chitosan
(CH) in complexes (NSC) prepared by tray drying (TD) and spray drying (SD) methods. Drug–polymer ratio (1:1) in the NSC was
optimized on the basis of dialysis studies. The particulate systems of NSC were prepared by tray drying (TD) and spray drying
(SD) methods. Release retarding polymers were added to the NSC and to the physical mixtures containing NS–CH and their effects
on water uptake, matrix erosion and drug release at different pH were compared. Spray dried complexes (SDC) were spherical,
free flowing, light and fine amorphous particles in contrast to the crystalline, hard, tenacious, irregularly shaped, denser
tray dried complexes (TDC) with poor flowability. Differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD)
and Fourier transform infrared (FTIR) patterns confirm the conversion of crystalline to high energy amorphous phase suitable
for ionic interactions in NSC. Presence of release retarding polymers, kappa carrageenan and hydroxypropylmethylcellulose
(HPMC) in the NSC compacts retarded the drug release and improved the matrix integrity. Carrageenan matrices exhibited more
retardation than HPMC tablets. FTIR patterns, erosion, swelling and drug release from matrices support ionic interactions
between NS and CH in NSC. The reasons for retarded drug release from the chitosan matrices at acidic pH include poor solubility
of drug at acidic pH, formation of a rate limiting polymer gel barrier along the periphery of matrices and the ionic interactions
between oppositely charged moieties. 相似文献
18.
The major aims of the present study were (1) to select a multiple-unit formulation that matched the in vitro dissolution profile
of single-unit sustained-release commercial capsules, (2) to compare the sustaining/controlling efficacy of the selected multiple-unit
formulation with that of the single-unit commercial conventional tablet and sustained-release capsules, and (3) to determine
whether an in vitro-in vivo correlation exists for single- and multiple-unit formulations. Ibuprofen (20%–60% wt/wt)-loaded
multiple-unit polystyrene microparticles were prepared by an emulsion-solvent evaporation method from an aqueous system. The
in vitro release profiles obtained in phosphate buffer of pH 6.8 for drug-loaded polystyrene microparticles and for commercial
sustained-release capsules (Fenlong-SR, 400 mg) were compared. Since the microparticles with 30% ibuprofen load showed a release
profile comparable to that of the Fenlong-SR release profile, the microparticles with this drug load were considered to be
the optimized/selected formulation and, therefore, were subjected to stability study and in vivo study in human volunteers.
A single-dose oral bioavailability study revealed significant differences in Cmax, Tmax, t1/2a, t1/2e, Ka, Ke, and AUC between the conventional tablet and optimized or Fenlong-SR capsule dosage forms. However, all the parameters, with
the exception of Ka along with relative bioavailability (F) and retard quotient (RΔ), obtained from the optimized ibuprofenloaded microparticles were lower than that obtained from the commercial Fenlong-SR
formulation. Furthermore, linear relationship obtained between the percentages dissolved and absorbed suggests a means to
predict in vivo absorption by measuring in vitro dissolution.
Published: September 1, 2006 相似文献
19.
Muhammad Harris Shoaib Saniah Al Sabah Siddiqi Rabia Ismail Yousuf Kamran Zaheer Muhammad Hanif Saeed Rehana Sabahat Jabeen 《AAPS PharmSciTech》2010,11(2):708-718
The objective of the present study was to develop a once-daily sustained-release (SR) matrix tablet of famotidine. Nine different
formulations (F1–F9) were prepared by direct compression method using Avicel PH101 as filler/binder in the range of 41–27%
in F1–F3, 18–22% in F4–F7, and 16–18% in F8–F9 and hydroxypropyl methylcellulose (4,000 cps) as hydrophilic matrix was used
in F1–F3 from 19% to 30%, around 40% in F4–F7, and 42–45% in F8–F9. Talc and Aerosil were added in the ratio of 0.7–1.2%.
The tablets were subjected to various physical parameters including weight variation test, hardness, thickness, diameter,
friability, and in vitro release studies. Assay was also performed according to the USP 30 NF 25 procedure. The results of the physical parameters
and assay were found to be within the acceptable range. In vitro dissolution results indicated that formulation F4–F7, having around 40% of rate control polymer, produced a SR pattern throughout
24 h. F1–F3 showed drug release at a faster rate, while F8–F9 released much slower, i.e., <80% in 24 h. Model-dependent and
model-independent methods were used for data analysis and the best results were observed for F4 in zero order (r
2 = 0.984) and F6 in Korsmeyer and Higuchi (r
2 = 0.992 and 0.988). The parameter n indicated anomalous diffusion, while β in Weibull showed a parabolic curve with higher initial slope. The f
2 similarity test was performed taking F4 as a reference formulation. Only the F5–F7 formulations were similar to the reference
formulation F4. The mean dissolution time was around 10 h for the successful formulation. 相似文献
20.
The present investigation aimed at formulation, performance evaluation, and stability studies of new vesicular drug carrier
system protransfersomes for transdermal delivery of the contraceptive agent, levonorgestrel. Protransfersome gel (PTG) formulations
of levonorgestrel were prepared and characterized for vesicle shape, size, entrapment efficiency, turbidity, and drug permeation
across rat skin and were evaluated for their stability. The system was evaluated in vivo for biological assay of progestational
activity including endometrial assay, inhibition of the formation of corpora lutea, and weight gain of uterus. The effects
of different formulation variables (type of alcohol, type and concentration of surfactant) on transdermal permeability profile
were assessed. The optimized PTG formulation showed enhanced in vitro skin permeation flux of 15.82±0.37 μg/cm2/hr as compared to 0.032±0.01 μg/cm2/hr for plain drug solution. PTG also showed good stability and after 2 months of storage there was no change in liquid crystalline
nature, drug content, and other characteristic parameters. The peak plasma concentration of levonorgestrel (0.139±0.05 μg/mL)
was achieved within 4 hours and maintained until 48 hours by a single topical application of optimized PTG formulation. In
vivo performance of the PTG formulation showed increase in the therapeutic efficacy of drug. Results indicated that the optimized
protransfersomal formulation of levonorgestrel had better skin permeation potential, sustained release characteristic, and
better stability than proliposomal formulation. 相似文献